Power transmission



June 25, 1940. D NN r AL 2,205,470

YOWEB TRANSMISSION Filod Oct. 26, 1957 5 Sheets-Sheet 1 I INVENTORS- nil/14m Tflwm BY Z.

61a P W I 'TTORNEY5- June 1940- w. 'r. DUN N El m. 2 0

rowan mmsussmn 7110:! Oct. 26, 1937 5 Sheets-Sheet 2 A TTOR NE Y June 25, 1940. w. 'r. DUNN ET AL.

rowan mlmsllzss-mn Filed Oct. 26, 1937 5 Sheets-Sheet 3 I INVENTORS. )MzZZzam 77 Z107, B 7? 770 Jaye-ZZZ" 44 @au I A TTORNE Y June 25, 1940. w 1', D r AL 2,205,470

BOWER TRANSIISSION Filed Oct. 26, 19:7 5 Sheds-Sheet 5 i U f a IN VENTORS.

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Patented June 25, 1940 PATENT OFFICE POWER TRANSMISSION William T. Dunn and Term Iavelli, Detroit, Micln, assignors to Chrysler Corporation, Highland Park, Mich, a corporation of Delaware Application October 26,

27 Claims.

This invention relates to power transmission mechanism and refers more particularly to improvements in power transmission systems especially adapted for use in connection with motor vehicles, although not necessarily limited thereto.

Our invention, in certain more limited aspects. provides improvements in the drive and control for power transmission systems having epicyclic or. planetary gear trains. It is customary, with such planetary transmissions, to arrange the gearing to provide for the desired number of speed ratios between the engine and vehicle driving ground wheels and such gearing is customarily selected and controlled to obtain the desired driving speed ratio by actuation of anyone of a group of transmission controlling devices usually consisting of reaction brake bands associated with and controlling the rotation of corresponding drums or similar elements of the various gear trains.

An object of our invention is to provide a novel and inexpensive means for providing, in response to the selection of a speed ratio, the desired degree of engagement of the selected speed ratio controlling device of the transmission, and remote control means for varying this degree of engagement.

Another object of our invention, in certain more limited aspects, is to provide a variable regulating means whereby the proper fluid pressure, which fluid pressure actuates the fluid operating means for controlling the brake bands and clutches of the planetary gear trains or other corresponding types of transmissions, is effected to provide in response to the selection of a speed ratio the desired degree of engagement of the selected speed ratio controlling device of the transmission; and whereby a suitable remote control is adapted to vary this degree of engagement from a predetermined low to a predetermined high fluid pressure. In the broader aspects of our invention, the fluid pressure is preferably provided by a suitable liquid medium such as oil, but the fluid pressure medium may be air under pressure greater or less than atmospheric pressure.

A further object of our invention resides in the provision of a simple and efficient means for regulating the well known swash plate pump-of such type as is described and claimed in the co-pending application of Augustin J. Syrovy, Serial No. 29,788, filed July 5, l935-in order to provide, in response tothe selection of a speed ratio, the dea'red degree of engagement of the selected speed ratio controlling device of the transmission; and

1937, Serial No. 171,165

the selected transmission speed ratio controlling device necessary to control the torque transmitted by that particular speed ratio; and to provide a selective range of pressures from a predetermined high to a predetermined low to control the aforesaid degree of engagement of the selected speed ratio controlling device.

I Further objects and advantages of our invention will be apparent from the following detailed descriptions of several illustrative embodiments of the principles of our invention, reference being had to the accompanying drawings, in which:

Fig. 1 is a side elevational view, somewhat diagrammatic in form, illustrating our power transmission mechanism as a whole.

Fig.2 is a detail elevational view showing the manually controlled selector element and the well known foot-operated pedals of a motor vehicle.

Fig. 3 is a sectional View of the manually controlled selecting mechanism taken as indicated by the line 3-3 of Fig. 1.

Fig. 4 is a sectional view along the line 44 of Fig. 3.

Fig. 5 is an enlarged sectional elevational view taken approximately as indicated by the line 5-5 of Fig. 1. Fig. 5-A is an enlarged detail sectional view takenalong the line 5A5A of Fig. 5.

Fig. 6 is an enlarged sectional plan view taken along line 6-6 of Fig. 1 through the transmission and fluid clutch. I

Fig. 7 is a sectional elevational view through the transmission, illustrating one ofthe speed ratio controlling devices and parts associated therewith, the section being taken as indic:.ted by the line of Fig. 6.

Fig. 8 is a rear elevational view illustrating the housing mechanism for the fluid pressure operator and associated control valve, the View being taken approximately as indicated by the line 8-8 of Fig. 6. v

Fig. 9 is a detail sectional elevational view taken along the line H of Fig. 8.

Fig. 10 is a detail sectional elevational view taken approximately as indicated by the line ll-l3 ofFlg. 6.

sponding to Fig. 11 but illustrating the swash plate pump in'its levelled of! condition.

Fig. 14 is a detail sectional plan view corresponding to rigs. 11 and 13 but illustrating the pump in its minimum pressure state.

Fig. 15 is a detail sectional elevational view taken as indicated by the line ll-li of Fig. 11. Fig. 16 is a atic view illustrating the electrical system of control between the manually operated selector element and'the fluid pressure control valve mechanism.

Fig. 1'1 is a detail sectional elevational view taken approximately as indicated by the linel1i1 of Fig. 11.

Fig. 18 is a detail sectional plan view corresponding to F18. 11 but illustrating another embodiment of our fluid pressure control for the transmission pump.

Referring now to the drawings, we have illustrated our invention in connection with a motor vehicle drive, this drive including a prime mover or engine A, a portion of which is shown in Fig. 1, a main clutch B driven from the engine, and a change speed transmission or gear box C driven from the clutch B. The drive passes from the transmission through the power take-off shaft 20, which, as usual, may extend rearwardly of the vehicle to drive the usual ground wheels (not shown) The clutch B may be of any suitable construction for controlling the drive between engine A and tron 0, this clutch being illustrated in Fig. 6 in the form of a fluid coupling type having the usual driving and driven cooperating vane members 2| and-22 respectively. The driving vane member 21 is carried by the engine flywheel 23, the latter being connected as usual with the'rear end of the engine crankshaft 24.

The driven vane member 22 is splined to a hub 25 which in turn is splined at 26 on the forward end of the driven shaft 21. This driven shaft extends rearwardly to drive the power take-oil? shaft 20 through the intermediary of the various gear trains of transmission C.

Where the power means for operating the transmission is afforded by a fluid such as oil under pressure, the pump for placing the oil under pressure is preferably operated from the engine to maintain the fluid pressure even when the pump is idling. It is therefore preferred to provide a pump drive from the driving clutch member 2| rather than the driven clutch member 22 inasmuch as the latter may be stationary under certain conditions of vehicle operation such as when the vehicle is standing still with the engine idling.

This pump drive may be provided by reason of a driving sleeve or hollow shaft 28 mounted on the shaft 21 but rotatable independently thereof. The sleeve 2! has a hub or flange 33 connected at 3| with the driving vane member 2| of the clutch B so that even when the driven vane member 22 is not being operated from the driving vane member 2i, the sleeve 29 will be rotatably driven from the engine crankshaft 24 and'flywheel 23. The'pump drive from sleeve 29 will be more apparent hereinafter.

We have illustrated the fluid type of clutch B since a clutch of this character has a number of advantages in connection with a transmission of the planetary gear type C and nection with our arrangement of vehicle driving controls which will be presently described more in detail. Among the advantages of the fluid type of clutch are the provision of a smooth drive for the vehicle through the planetary transmission, relatively high power driving efliciency, automatic release of the drive between the engine and transmission when the engine is idling, and with the'tran'smissionmanipulated to establish one of its driving gear ratio settings, and other well known favorable characteristics.

We have illustrated the change speed transmission 0 as the epicyclic or planetary type, this general form of transmission being well known in the art and, as usual, includes a plurality of transmission speed ratio controlling clutches or brakes 32, 33, 34 and 35, these braking controlling devices being respectively adapted to actuate the transmission' in its first speed ratio or low gear, second speed ratio orintermediate gear, third speed ratio or direct drive, and reverse drive. Other speeds may be provided as desired.

The typical brake device 32 illustrated in Fig. 7 consists of an outer band 36 which substantially surrounds the rotary element or drum 31, the band being provided with friction braking material 33 carried by the band and adapted for frictional engagement with the drum 31. The band 36 has its ends formed with laterally projecting actuating flanges 39 and 43 positioned adjacent each other, means being provided to move the band ends toward each other to contract the band 36 for causing the friction ma terial 38 to brake rotary drum 31, the band having suflicient inherent resilience to expand away from contact with the drum when the actuating means is relieved at the flanged ends 39 and 40. In Fig. 7 the low speed ratio braking device 32 is illustrated in its inoperative position whereby the drum 31 is free to rotate through operation of the planetary gear set 4| somewhat diagrammatically illustrated in association with the drum 31. When the braking device is actuated by contracting the band stance being operated through the planetary gearing 4| to provide the low speed drive for the motor vehicle.

In order to anchor the band 36 and to substantially equalize the braking forces applied to drum 31 around the periphery thereof and thereby substantially avoid a tendency toward lateral loading of the drum and planetary gearing transverse to the axis of the drum, we have provided the band with a circumferentially spaced pair of anchoring flanges 42. These flanges are connected through" links 43 with the levers 44 pivotally mounted at 45 with the supporting bracket 46 of the transmission side cover casing 41, the levers 44 being interlocked at 48 so that movement of one of the flanges 42 will be transmitted through the pivotal levers 44 and the links 43 to the other portion of the band associated with the anchoring device. The links 43 are thus pivotally connected at their opposite further con-' 35, the drum 31 is held. against rotation, the driven shaft 20 in such in-' ends respectively with the anchors 42 and levers 44.

The third speed clutching controlling device 34 is arranged for a direct drive through the transmission and differs somewhat from the braking devices 32, 33 and 35 in that the controlling device 34 has its rotary controlling element 58 adapted for clutching action in a well known manner by frictional engagement through the discs 5| by an axially movable clutching member 52. The latter clutching member is thus engaged by the yoked end 54 of an actuating lever 55 pivotally mounted bya pin 58 suitably supported in the transmission casing. 0n the opposite side of pivot 55 the lever 55 is'provided with a step actuating portion 59, the purpose of which will presently be more apparent.

The transmission casing portions 58 and 58 are respectively provided with the vertically spaced inwardly extending supporting brackets 52 and 53, respectively, these brackets being. formed with coaxial splined openings 84 and 55, 1

respectively. Splined within these openings are the nuts 55 and 51 which are axially and oppositely threaded to receive the correspondingly threaded ends 58 and 59 of an operating oscil latory shaft or screw 18.

The shaft I8 extends through openings II and 12, respectively, formed to open laterally in the aforesaid band ends 39 and 48, these openings having considerable clearance with shaft 18 so as not to bind on the shaft when the band .is contracted and expanded. In order to transmit the thrust of the nuts 88 and 51 to the flanges 39 and 48 so as to relieve distorting loads on the shaft 18 and parts associated therewith, each nut operates a sleeve I3 having a curved face. 14 engaging a curved face I5 of bandend 39 or 48. The engaged curved faces 14 and 15 provide a rocking freedom of action, each sleeve 13 having a clearance indicated at 18 with the shaft 18.

The operating-shaft 18 of the low speed braking device 32 has its portion thereof intermediate the band ends 39 and 48 formed with a gear TI, the means for oscillating shaft 18 through the gear I1 being hereinafter more particularly described. v

In the operation of the low speed controlling device 32, as thus far described, it will be apparent that when the shaft 18 is given a rotary movement, such movement operates through the oppositely threaded ends 88 and 89 of the shaft 18 to cause the nuts 86 and 51 to move inwardly toward each other in their splined openings 64 and 85, respectively, this movement acting through the sleeves 13 to contract the band ends 39 and 48 whereby the low speed drum 31 has its rotation checked for establishing the low speed drive through the transmission. When the shaft 18 is rotated in the opposite direction, the nuts 65 and 8l are moved away from each other and the band 35 is expanded to permit the drum 3'! to again rotate and thereby relieve the drive through the transmission controlling device 32.

In order to avoid repetition we have not illustrated all of the details of the brake operated means associated with the controlling devices 33 and 35, it being understood that such operating means are similar to that described in connection with the controlling device 32. For convenience of reference the operating shaft or screw for the reverse speed braking device is designated as 18" and the corresponding shaft for the second speed braking device 33 is designated as 18 The gears associated with these screw shafts are respectively designated as H and 11''. As will be more apparent presently, the gears l1, l1 and 'Il and lever end 59 are adapted to be selectively operated in order to selectively control the engagement and release of the respective speed ratio controlling devices 32, 35, 33 and 34.

' We will next describe the common operating means or selector operating element which is adapted for selective engagement under manual control with the aforesaid screw gears TI, 11 and 11 for respectively operating the speed ratio controlling devices 32, 35 and 33; also for operating the direct or third speed controlling device 34; and also for establishing a neutral condition in the transmission.

The transmission casing is adapted to support in a forward opening 18' the reciprocating and oscillating rack or actuating shaft D. The rear bearing for shaft D is provided by a member 19 which is disposed in a suitable opening 88 in the rear end wall 8| of the transmission casing 8i, the rear end of the actuating shaft D being also supported by a piston for reciprocating the shaft and which will presently be referred to in detail.

This actuating shaft D has a; series of teeth forming a rack adapted to be brought into operative association with each of the screw gears, these racks being designated at 82, 83 and 84 for respectively operating the screw gears 11, TI, and 11 The forward endof shaft D is further provided with a third speed actuating projection 85 adapted for engagement with the lever shoulder 59 for operating the third speed controlling device 34. It will be noted that the racks and projection 85 are longitudinally spaced along the shaft D and that they are also spaced circumferentially of the shaft whereby upon progressive rotation of the shaft only one of the racks and the projection 85 will engage its associated screw gear or lever 55 at any time.

In Figs. 6 and 7 it will be noted that the shaft D is positioned so that the low speed rack 82 is in position for operating the low speed gear 11 and when the shaft Dis moved forwardly or to the left as viewed in Fig. 6, the low speed screw 18 will be rotated to cause the aforesaid braking operation of the low speed controlling device 32 for establishing the low speed drive through the transmission. It will, furthermore, be noted that with the low speed rack 82 in the position illustrated, the remaining racks 83, 84 as well as projection 85 are free from engagement with their respective associated gears 11, 11 and the lever 55. From Figs. 6 and 7 it will be noted that the shaft D has a space longitudinally and circumferentially between the second speed rack 84 and the direct drive projection 85, this space being designated as the neutral space N so that when the shaftis positioned with this space facing the screw gears, each of the racks as well as projection 85 will be free from contact with their associated screw gears and lever 55, and the transmission will be in neutral at which time the various braking devices 32, 33, 34 and 35 are released.

In orderto selectively rotate the rack D for selectively engaging the racks and projection 85 thereof with the respective screw gears and lever 55, and also for axially operating the shaft in the various-positions of selective adjustment, the following mechanism is provided.

Rearwardly adjacent the reverse rack 83, the shaft D is provided with a circular rack or gear 85 meshing with a segmental rack 81 rotatahly journalled by a bearing 89 carried by the transmission side cover 99. The shaft 99 has fixed thereto, outwardly of the transmission cover, a lever 91 connected at 92 (see Fig. 1) to a Bowden wire operating mechanism 93.

The Bowden wire operating mechanism 93 extends forwardly for pivotal connection with a.

ball end 99 of a lever assembly 95 secured to a tubular shaft 96 as shown in Figs. and 5A. The forward end of the Bowden'mechanism has a guide 91 provided by the bracket 99 rigidly secured to the outer stationary tubular housing 99 comprising the steering post, as best shown in Fig. 1. A yielding connection is preferably provided at some convenient point between the manual selector element, which will be shortly described, and the segmental rack 9'1 for rotatably adjusting the shaft D. We have illustrated this yielding connection in Fig. 5A intermediate the lever ball end 99 and the forward end of the Bowden wire mechanism 93. The wire 93 is anchored at its forward end to a housing I99 provided with preloaded oppositely acting springs III and I92 which respectively act against the ball seats I93 and I99. The springs IM and I92 have sufficient rigidity so that normally they provide a rigid connection between lever 95 and Bowden wire 93. However, if for any reason the manually operated adjusting mechanism for the shaft D should bind at any point, the mechanism will be protected during any manual ad- .justment -of lever 95 under such conditions by reason of the ability of springs IM and I92 to yield. This yielding connection is'therefore in the nature of a safety device for the manually controlled selector operating mechanism. The

hollow operating shaft 96 extends within the housing 99 and is suitably rotatably journalled therein.

Rotatable within the hollow shaft 96 is the hollow steering shaft I91 operably connected at its upper end to a steering wheel I 99 and adapted for operable connection at its lower end to the usual steering mechanism for the front ground wheels of the motor vehicle (not shown). The hollow operating shaft 96 extends upwardly to the point preferably just below the steering wheel I 99 to the manually controlled device generally designated at E for selectively controlling or manipulating the transmission speed ratios as will be presently more apparent.

Returning now to Fig. 6, the selector rack shaft D has its rear end adjacent the circular rack 96 provided with a groove I99 adapted to receive the flange II9 of the fluid pressure operating piston assembly Ill adapted for reciprocal movement in the cylinder I I 2 which'is apart of a casting II3 best illustrated in Figs. 8 and 9 as attached at II9 to the rear wall of the transmission. The piston III provides the actuating member of the power operating means G for moving shaft D under power to engage the various brake bands and the direct speed clutch 39.

For yieldingly urging the rack shaft D to the right or rearwardly to release the speed ratio controlling devices, we have provided prime mover means F preferably in the form of a compression coil spring surrounding the rear end portion of shaft D between the fixed abutment pro-' vided. for the bearing member I9 and acting on piston III In Fig. 6 it will be noted that the bearing member 19 is conveniently held in position by clamping the same between the rear casin: wall 9| of the transmission and the casting The piston III has a flexible sealing cup H5 adapted to seal the piston against escape of the fluid forwardly of the cylinder II 2, the cup [I5 bearing against the walls of the cylinder under the action of the fluid pressure introduced to the pressure chamber 9. The sealing cup is held in-place by the 'rearwardly extending threaded reduced end II1 of shaft D together with a fastener or nut II9. Fluid, such as oil under pressure, ,is introduced to the pressure chamber IIG as best shown in Fig. 9, through a e II9 leading to the valve controlled chamber or cylinder I29 which slidably receives the fluid pressure supply controlling valve I 2|. The cylinder I29 is supplied with oil under pressure through a passage .I22 which receives the oil by a conduit I23 formed'in the transmission casing casting. The conduit I23, as best shown in Fig. 1, leads to the delivery side of a swash plate type pump H driven from its location in the oil storing sump or reservoir I29 of the transmission casing by reason of the shaft I 25 provided at its forward end by a driving gear I29. I This gear meshes with an idler gear I21 which in turn meshes with the driving pinion. I29 (see Fig. 6) carried on the rear end of the driving sleeve 29 which, as aforesaid, is fixed to the fluid impeller 2|.

A valve guide porting member I29 is pressed into the cylinder I29 so as to be fixed therewith, this porting member having annular conduits I39 and III, respectively, communicating with the passages I 22 and H9. The annular passages I39 and. I3I are also respectively provided with the inwardly extending ports I32 and I33 adapted for control by the valve I2I. This valve has a sliding fit within the cylindrical bore I39 of the porting member I29 and extending axially through the valve with sufficient clearance to prevent binding thereof, is a valve operating rod I35 preferably of brass or other non-magnetic material. The rod I35 extends forwardly of valve I2I and is provided with a stop I36 adapted to limit forward movement of valveI2I under the influence of a spring I31 which operates between a valve spring abutment I39 and a rear fixed abutment I39, the latter having associated therewith the fluid pressure sealing washers I99 acting against the threaded stem I of the electrical solenoid I92.

The rear end of valve operating rod I35 is connected at" I93 with the armature I99 of solenoid I92, the armature being adapted for reciprocation in the solenoid cylinder I95 having the rear abutment I99. Any fluid which may leak rearwardly beyond the valve I2I is adapted to drain downwardly from the portion of casting II3 which encloses 'the valve operating spring I31 by reason of the drain conduit I91, this conduit then extending forwardly to the main body of the transmission where the oil is permitted to drain back to the reservoir I29. A further conduit I99 is adapted to return the oil from operating cylinder II6 back to the reservoir, this conduit I98 opening rearwardly to the forward end of valve IN.

The valve I2I has the reduced valving portion I99 adapted to place the conduits I22 and H9 in communication when the valve is in its forward position under the influence of spring I31. In the drawings, the parts are shown in their positions for operating the low speed controlling device 32, the valve I2I being positioned forwardly so that the fluid pressure is just being delivered from the supply conduit I22 to the conduit II9 and the pressure chamber II6 of the cylinder 7 k for arcuate adjustment. selector lever is provided with a knob or handle II2. When the valve I2I moves rearwardly under the influence of solenoid I42, as will be presently more apparent, the spring I31 will be compressed and the reduced portion I49 will no longer provide communication between conduits I22 and H9. At such time the conduit II9 will be open through the port I33 to the discharge conduit I48 for returning the oil from the pressure chamber II6 back to the reservoir I24. When the valve I2I moves forwardly under the influence of spring I31, the reduced valve portion I49 aiford's communication between conduits I22 and H9 to supply fluid pressure from the pump H to operate the piston III and selector rack shaft D forwardly for actuating one of the speed ratio controlling devices 32, 33, 34 or 35, depending on the rotative selective adjustment of the selector rack shaft, as will be presently more apparent.

The function and operation of the manually controlled selector mechanism E in relation to the selector rack shaft D will now be further described.

- Secured to the upper end of the hollow operating shaft 96, as best seen in Fig. 4, is an annular collar I50 having an integral laterally extending projection I5I providing an abutment for a spring I52 which has its lower end yieldingly acting against an intermediate portion of a manually operated selector element or lever I53. It will be noted that the extension I5I projects through an arcuate opening I54 of the fixed housing 99 to accommodate oscillatory adjustment of the extension I5I.

The inner end of selector lever I53 is pivotally mounted at I55 to an intermediate portion of the collar extension I5I so that the selector lever may have vertical movement on pivots I55 relative to the extension I5I but when lever I53 is moved around the axis of the steering post housing 99, the collar I50 together with the extension I 5I and the shaft 96 will be rotatively moved as a unit. 1

Fixed on the upper end of the'housing 99 is a housing I56 preferably in the shape of a sector. The outer end of this housing has a downwardly extending flange I51 provided with an arcuate opening I58 through which the lever I53 extends The outer end of the I59 adapted for convenient grasp by'the hand of the motor vehicle driver.

The outer curving edge of housing I56 is preferably formed with a number of legends characterizing the various positions of manual adjustment of selector lever I53 depending on the number of stations of adjustment for this lever. In the particular embodiment illustrated, the selector lever I53 is adapted to have five positions of adjustment, I60, I6I, I62, I63 and I64 hearing the legends indicated in Fig. 3 designating the lever positions corresponding to first, second, third, neutral and reverse conditions of control for the transmission.

The flange I51 of housing I56 carries an arcuately arranged switch mechanism below the selector lever I53, this mechanism being, best illustrated in the wiring diagram of Fig. 13. This switch comprises an arcuate floor I65 provided with a series of grooves or notches I66, I61, I68, I69 and I10 corresponding, respectively, to the positions of selector lever I53.when adjusted to the stations I66 to I64, inclusive. The upper sides of the aforesaid notches are preferably chamfered or beveled, as shown in Fig. 13, and the portion of selector lever I53 ensaseable with these notches is likewise beveledas indicated at When the operator desires. to select any condition of control of the transmission, he "swings the selector lever I53 into the desired position, the spring I52 yieldingly urging the selector lever downwardly into engagement with one of the notches of the switch member I65.

Referring now to the wiring diagram illustrated in Fig. 16, we have provided a plurality of switches or contacts I12 for each of the notches of the switch member I65 and being adapted for operation by a stem I13 slidable in an opening I14 communicating with each of the switch notches so that when the selector arm is located in any of the switch notches, one of the stems I13 associated with such notch is engaged,

by the selector lever and is pushed downwardly by the spring I52 to break the current through the .wire I15 which connects all the switches I12 in series. Each switch I12 has a spring I16 associated therewith for restoring the switch to its contacting position and raising its stem I13 as soon as the selector lever is moved out 'of one of the notches. The wire I15 connects with one terminal of a storage battery I11, the other end of wire I15 being connected to the windings I18 of solenoid armature I44 aforesaid, which is grounded at the other terminal of battery I11. A wire I19 is electrically interposed at I69 and I8I between the extremes of wire*l15 to be arranged in parallel with wire I15, a single switch I82 being carried by wire I19 to normally break this circuit as illustrated and under'such conditions as will hereinafter be more apparent.

Our manually controlled selector operating mechanism is practically instantaneous in its response to selective adjustment of the lever I53 and the different selections may be made as rapidly as desired. In the general operation of the selector mechanism E for changing the transmission speed ratio, the operator moves the selector lever I53 from one of the station notches in the switch member I65. Just as soon as the selector lever is moved from one of the notches, the switch I12 associated with such notch will be closed, thereby inducing an electrical circuit through the solenoid windings I18 for causing the solenoid armature I44 to move rearwardly against the abutment I46. This rearward movement of the solenoid armature will adjust the valve I2I rearwardly to place the fluid pressure 'chamber II6 of cylinder H2 in communication with the reservoir discharge conduit I46 whereupon spring F will move the shaft D rearwardly to release any of the controlling devices 32 to 35 which might have been in operation. This entire phase of the operation takes place very quickly during the initial part of adjustment of the selector lever out of one of the notches of the switch member I65. The selector lever I53 may then be moved into any other station of control and dropped into the corresponding notch for such position.

I When the selector lever is so released it will be apparent that one of the switches I12 corresponding to such newly selected position will be opened, thereby interrupting the electrical circuit through the wire I15 to the solenoid windings I18- At such time the spring I31 will immediately act to move the valve I2I and armature I44 forwardly to establish communication between the fluid pressure supply conduit I22 and the pressure chamber II6. This will imling devices. The mechanism operates almost mediately cause a forward movement induced of pistons I88. A forward abutment member 288 by the fluid pressure on the shaft D for operatis slidable on rod I88, as will presently be more ing one of the selector controlling devices which apparent; and serves as a forward stop for the may have been selected for the new position or spring 288. else for operating shaft D without causing any A yoke portion I88-best shown in Figs. 11 and movement of any of the speed ratio controlling devices in the event that neutral was selected. hold a rear abutment member 288 against the Returning now to the aforesaid cycle of opaccumulator spring 288 in a pro-loaded condition. eration and to the point where the selector lever The accumulator piston rod I88 has formed I 53 was described as having been moved out of thereon a cylindrical portion 288 which is norone of the notches preparatory to movement mally positioned away from the abutment memthereof into a newly selected notch, just as soon her 288 as illustrated in Fig. 11, but is capable of a th solenoid armature I 88 moves rearward y being moved with the piston rod I88 into contact to operate valve I2I to vent the pressure chamwith the member 288 as in Fig. 13, without strike ber II8, it will be apparent that the fluid presing the yoke portion 288. when the piston 283 sure load is removed from the shaft D which is isurged forwardly by fluid pressure within cylnow in its rearward position so that arcuate inder 282, as will hereinafter be more apparent, movement of the selector lever I53 will oper the forward end of rod I88 acts within recess 28I through the hollow steering post shaft I8 0 force the rocker beam counterclockwisely Bowden wire mechanism H2, and sector 81 to und the fulcrum I8I until the cylindrical porrotatably adjust the shaft D into a new position tion gontacts the abutment member 288-and for actuation of one of the speed ratio controlupon additional pressure build-up within cylinder 282. the portion 288 moves the abutment member 288 just sufllciently to carry it away from the yoke portion as in Fig. 13, and to thereby have the portion 288 take the force of the spring 288 acting through the abutment member 288, at which time the pump swash plate I88 is balanced and the fluid pressure is at its minimum.

As described, the piston 283 moves forwardly in response to the fluid pressure within cylinder 282 instantaneously so that there is practically no resistance to immediate arcuate adjustment of selector lever I53 from a position in one of the notches although any binding tendency experienced at the shaft D during the initial or other tendency to move the shaft will be taken up yieldingly through the Bowden wire connection shown in Fig. 5A.

Referring now to the details of the pump H and our variable pressure regulating means therefor, the pump assembly includes a casingstrueture I83 adapted to be attached to the transmission structure as illustrated in ,Figs. 1 and 11. The casing receives the pump drive shaft I25 aforesaid, which is suitably journalled. at I88 and I85 by the casing. Shaft I25 is illustrated with its gear I28 (best shown in Fig. 1) in constant mesh with idler gear I21 which in turn is drivingly connected with the fluid impeller associated driving pinion I28. A pump rotor I88 is drivingly connected to shaft I25. Inlet and outlet passages I81 and I88 respectively supply and deliver fluid in the well known manner to the inlet and outlet ports of the pumping cylinders of rotor I85. The pistons I88 are adapted to operate in the well known circumferentially spaced cylinders opening inwardly toward a wabble or swash plate I88.

The pistons are urged rearwardly in the well known manner, as is described and claimed in the aforwaid application No. 28,788, into'contact with the swash plate I88, the inner rounded'end of each piston slidably engaging an outer ring I8I which is rotatably supported by plate I88. A suitable pivotal support is provided for plate I88 at I82 on the casing I83. The other side of plate I 88 is pivotally connected at I83 to a forwardly extending link I88 pivoted at I85 to a rocker beam I88.

A suitable knife edge fulcrum I8I on casing I83. is adapted to act against a recess I88 provided by the forward face of beam I86. To oppose the rearwardly acting forces of fulcrum I81 and link I88, the forward end of an accumulator piston rod I88 of a pressure accumulator 288 is adapted to act against the beam I88 through a suitable recess 28I as will presently be more apparent.

Slidable in a cylinder 282 carried by casing I83 is a piston 283 which is:adapted under certain conditions to be urged inwardly by a heavy spring 288, the rod. I88 being fixed to piston 283 in order to swing the beam I88 for levelling-off the plate I88 and minimizing or eliminating reciprocation intermediary of outlet passage I88 and a conduit 2I8 to an inlet 2| I of the accumulator cylinder 282. The fluid under pressure is led to a suitable point of usage from cylinder 282 through a casing passage 2I2. The rearward wall of casing I83 closes off the inner end of cylinder 282.

As the shaft I25 drives rotor I88, with plate I88 positioned as in Fig. 11 for maximum stroke, approximately half the pistons I 88 are moving inwardly drawing in oil through the inlet passage I81, while the remaining pistons are discharging oil underpressure through outlet passage I88 for passage to cylinder 282 inthe well known manner.

When the pump H is initially operated, providing the abutment member 285 is in its Fig. 11 station, the pressure of the oil delivered at inlet 2 to cylinder 282 rapidly builds up to the pressure (determined by the value of spring 288) required to energize the first speed ratio controlling the piston 283 moves outwardly to increase the capacity of cylinder 282. During this forward movement of rod I88 to its position of Fig. 13, the rocker beam I88 swings plate I88 about its pivot I 82 into a position approximately transverse to the axis of shaft I25. This levelling-oil! of plate untilthey are substantially motionless so far as reciprocation is concerned, assuming of course that oil under pressure is not being relieved from may be present in the delivery system or any movement of the abutment member 285 rearpistons to maintain the maximum desired oil pressure in cylinder 282.

The accumulator cylinder 282 stores oil under pressure so that when oil is delivered under pressure at passage 2I2, the spring 288 expands and tends to prevent an otherwise rapid fall of the fluid pressure. I

When the yoke portion 288 is movedforwardly slightly under the Fig. 13 or maximum fluid pres- 15-of a shifter fork 281 is adapted to normally.

as the fluid is delivered by pump B through the' device 32 and as this pressure is being built up.

I88 progressively lessens the stroke of pistons I88- the delivery system. Any minor leakages which -85 wardly will require only a small movement of the sure condition of pump H, the abutment member 298 is just taken away from its seat on the forward end of the piston rodlcylindrical portion 299 -during which movement the fluid pressure is gradually reduced toits predetermined minimum pressure by reason of the pressure chamber not having so great a forceto overcome inasmuch as the pressure of the accumulator spring on portion 299 is gradually reduced. We prefer to use a minimum fluid pressure of about one-third of the ing of the switch I82 when the pedal 213 is about fully depressed against an adjustable stop 22I.

It will be noted in the Fig. 16 electrical diagram that .when the switch I82 is closed, a circuit is completed through wire I19 between the wire I15 and the solenoid windings I19. It is thus evident that the closing of switch I82 will cause the solenoid armature I44 to move rearwardly to abutment I46 even though one of the switches I12 is open to break the circuit through wire I15. This rearward movement of armature I44 would also be effected when the switch I82 is closed, although all the switches I12 are closed at that time by reason of the vehicle driver lifting the selector lever I53 to select another speed ratio. The rearward movement of the armature I44 opens the conduit II9, through the port I33, to the discharge conduit for returning the oil from the pressure chamber I 18 back to the reservoir 124. This armature movement effects a complete release or neutral position for each of the controlling devices 32, 33, 34 and 35 so that no drive is transmitted to the power take-off shaft 29.

Upon the beginning of the return movement of the pedal to its Fig. 1 position, the link support 2I1 allows the arm 2I9 to return to its normal position of Fig. 1 at which time the electrical circuit through wire I19 is broken. The breaking of this circuit causes the armature 144 to return to its illustrated station of Fig. 9 under the influence of spring I31, the reduced valve portion I49 again affording communication between conduits I22 and H9 to supply fluid pressure from the pump H to operate the piston III and rack D forwardly for actuating one of the speed ratio controlling devices 32 to 35.

Any suitable remote control may be used with our variable pressure pump regulating means, but we prefer to illustrate our invention with a movement reducing linkage wherein a hollow cylinder 222 (best shown in Figs. 1 and 12) has a closed end provided with an articulated connection 223 on bell crank arm 224 of pedal 2I3. Inside this cylinder 222 is a preloaded coil spring 225 which extends beyond the open end of cylinder 222 and against an end cap 228. A spine member 221 is suitably fixed to an end cap 226 and is adapted to reciprocate within spring 225 to prevent lateral movement of this spring.

A pivotal support 228 for end cap 228 is provided by a link member 229, the other end of this link member having fixed thereto a shaft 239 which extends, inwardly toward the vertical longitudinal mid-plane of the transmission C. The

shaft 239 is rotatably supported by the casing 8| at 23I and 292 and is adapted to transmit ts axial movement to the shifter fork 291 throu h a suitable locking means such as key 233-best shown in Fig. 15.

By depressing the face 234 of pedal 2I3 until the pedal strikes the stop 221, a comparatively long are of arm 224 is reduced by cylinder 222 compressing the spring 225 as illustrated in Fig. 12, thus effecting but a very short are of movement of pivotal support 228 about shaft 239. This movement-reducing linkage thereby, with a comparatively longer are of movement, regulates our variable regulating means which requires a shorter control movementthe spring 225 tending to return the pedal 2I3 to its Fig. 1 position.

The relationship of the bell crank arm 224 to the support 228 of link member 229 may be made, if desired, so that'as the pedal face 234 is depressed to substantially one-third of its complete travel, the member 229 will swing sufficiently to transmit forward movement to the yoke portion 298 for causing the yoke portion to carry the abutment member 298 sufficiently away from the cylindrical portion 299 in its maximum pressure position of Fig. 13 to reduce the pump pressure to about one-half of its aforesaid maximum fluid pressure in the earlier described manner. As the pedal face 234 continues to move toward the stop 221, the yoke portion 296 moves the abutment member 298 forwardly to its predetermined minimum fluid pressure station of Fig. 14 and the pressure of the spring 294 against the cylindrical portion 299 is relieved entirely in order to cause the pump pressure to be reduced to the aforesaid predetermined fluid pressure of about one-third.

of the maximum pressure. I

At the extreme end of the movement of the pedal face 234, the link 2I9 closes the switch I82 for actuating the solenoid armature I44 to release the controlling devices 32 to 35.

One feature of our invention resides in the simple control that is possible with our novel transmission system, one preferred embodiment of this control being illustrated in Fig. 2 wherein it will be observed that the selector lever I53 is positioned for manipulation laterally to the right of the steering wheel I98 for effecting a change in the condition of the transmission. Our transmission provides for convenient manipulation of the motor vehicle by providing the engine throttle control or accelerator pedal 235 preferably at the right hand side of the steering post'99 so that it may be manipulated by the right foot of the driver. On the same side of the steering post is a pedal 236 which is adapted to operate the wheel brakes of the motor vehicle, and on the other .side we have provided the pedal face 234 for convenient manipulation by the left foot of the vehicle driver. The pedal face 234 is thus apparently the well known friction plate clutch pedal, and has the same feel when operated by the vehicle driver, as will presently be more apparent.

In addition to the speed ratio device engagement control provided by the actuating of the pedal face 234 whereby the fluid pressure of the pump H is,regulatable from a predetermined maximum to a predetermined minimum fluid pressure, we also provide a control wherein our variable regulating means may provide in response to the selected speed ratio controlling device the proper pressure for accommodating the torque transmitted by the engine through that particular speed ratio. Heretofore it has been general practice touse the same pressure for energizing each of the speed ratio controlling devices of the transmission, and this was undesirable in many instances because a compromise had to be'rnade so that the pressure was usually either too high or too low for smooth and quiet actuation, without excessive slippage or grabbing, of most of the speed ratio controlling devices.

To this end we prefer to illustrate our invention with a control responsive to the selection with the selector handle I53 of one of the stations I60, I6I, I62 and I64 to energize the speed ratio controlling devices 32, 33, 34 and 35, respectively-it being understood that other speed ratios may be provided if desired without departing from the scope of our invention.

A suitable means may be employed to adjust one of the members of our pressure pump regulator in response to the selection of a speed ratio with the selector handle I53, and to effect this a cam link 231 (best shown in Fig. 7) is appropriately supported by the segmental rack 81 at 238 for movement with the latter and adapted to reciprocate vertically within an extension 239 of the transmission casing portion 58 in response to movement of the selector lever I53.

As illustrated, the link 231 is in its first speed position by reason of'the selector lever I53 engaging the first speed station I60, and is adapted to place its first speed cam surface 240 adjacent one of the arms of a bell crank 24I. Two other cam surfaces 242 and 243 for second and high, and for reverse speed ratio respectively have been provided on link 231. It is readily evident that the reverse speed surface 243 permits the bell crank 24I (best shown in Fig. 11) to move downwardly further than the first speed surface 240, which in turn has greater effective height than the second and third speed surface 242. We prefer to combine the second and third speeds for the one surface 242 inasmuch as substantially the same torque is transmitted through these speed ratios of the illustrated transmission, although separate cam surfaces may be provided for each of these speeds, or additional speed ratios and cam surfaces may be added, without going beyond the scope of our invention. The effect of these progressive cam surfaces 243, 242 and 240 is to change the pressure pump system a predetermined amount in order to cause the pump H to level off at a definite fluid pressure to effect the desired degree of engagement of the selected speed ratio controlling device.

The bell crank 2 is pivotally supported at 244 on casing structure I83 and a yoke portion 245 is adapted to control the fore and aft move-- -ment of abutment member 205. The ratio of the bell crank arms,,the effectiveheight of the cam surfaces 243, 242 and 240, and the rate of the spring 204 are such that the degree of contraction of the spring 204 in the selected speed ratio will control the spring pressure against the rear abutment member 208 so that as the cylindrical portion 209 takes the load away from the yoke portion 206 in Fig. 13 it will have to bear the adjusted pressure of the spring 204 to place the fluid pressure system in equilibrium after this condition has been accommodated by the pump pistons I89 reciprocating slightly, if necessary.

In our illustrative embodiment the cam surfaces 243, 240 and 242 respectively cause the yoke portion 245 to progressively allow the spring 204 to expand and relieve the pressure on the abutment member 208, thus causing the pump to level off at a predetermined fluid pressure for each particular speed ratio.

The maximum forward travel of member 205 may be effected by an extension 246 of the casing I83 obstructing the inwardly swinging of the.

.bell crank I. To normally maintain the bell crank 2 in substantially its Figs. 11 and 13 positions and to allow the link 231 to be moved vertically in response to the selection of another speed ratio, a, suitable piston 241 has a finger portion 248 in contact with a recessed end porby overcoming the opposing force of the spring 204 tending to move the yoke portion 245 forwardly.

Under this condition the fluid pressure system, assuming, of course, that -oil under pressure is not being relieved from the delivery system and the pedal 2I3 is in its illustrated station of Fig. 1, will build up to its aforesaid predetermined fluid pressure for that particular speed ratio wherein the plate I90 progressively lessens the stroke of pistons I89 until they are substantially motionless so far as reciprocation is concerned. However, if the vehicle operator then desires to select another speed ratio or neutral, he lifts the lever I53 in doing so and the switch I12 associated with the notch I66, I61, I88, I69 or I10 will be closed-thereby inducing an electrical circuit through the solenoid windings I18 for causing the solenoid armature I44 to move rearwardly to adjust the valve I2I to place the fluid pressure chamber II6 of cylinder H2 in communication with the reservoir discharge conduit I48 to effect a release of any of the controlling devices 32 to 35 which might have been in operation.

During this opening of the chamberI I6 to the reservoir conduit I48 the escapeof fluid lowers the pressure within the accumulator cylinder 202 and .the conduit 2I0 to substantially zero-at which time the fluid pressure in the cylinder 25I is consequently reduced so that the force of the spring 204 movesthe yoke portion 245 forwardly in opposition to the reduced pressure in the cylinder 25I. This entire phase of the operation occurs very quickly during the initial part of adjustment of the selector lever out of 'one of the notches of theswitch member I65.

The reduction of pressure in the cylinder 25I permits the vehicle operator to move the selector lever I53 into any other station of control inasmuch as the cam link 231 moves vertically to its newly selected position by pressing the end portion 249 inwardly. When the selector lever I53 is so released it will be apparent that one of the switches I12 corresponding to such newly selected position will be opened, thereby interrupting the electrical circuit through the wire I15 to the solenoid windings I82. Atsuch time the spring I31 will immediately act to move the valve I2I and armature I44 forwardly to establish communication between the fluid pressure supply conduit I22 and the pressure chamber II6. This will immediately cause a forward movement induced by the fluid pressure on the shaft D for operating one of the selector controlling devices which might have been selected for the new position or else for operating shaft D without causing any movement of any of the speed ratio controlling devices in the event that neutral was selected. Immediately upon this forward movement of valve I2I' the fluid pressure system is again closed and theitroke of the pistons is increased to effect the fluid pressure determined by the newly selected cam surface and its effect on the spring 204 through the piston 241 and the bell crank 2.

The function of the pedal control is independent of the bell crank 2 control to the extent only that the pedal may be depressed to any degree at any time to vary the pressure of the spring 204 on the cylindrical portion 203 to reduce the fluid pressure to zero with the aid of the switch I82 in moving the valve I2I forwardly. During this change in fluid pressure the pressure on the piston 241 will vary accordingly so that the spring 204 will have less and less force to overcome in moving the yoke portion 245 forwardly, so that the vehicle driver may select the speed ratios, as described earlier, with desirable characteristics of slippage as effected by his control of the pedal 2I3. It is obviously evident that the vehicle operator need not depress the pedal at all, inasmuch as the lifting of the lever I53 .will adjust the valve I2I rearwardly to place the fluid pressure chamber 8 in communication with the reservoir discharge conduit I48 at which time the fluid pressure in the cylinder 25I is reduced to permit the cam link 231 to be adjusted to its new position when the selector lever I53 is swung to its newly selected notch and released therein to cause the valve I2I to move forwardly to operate the transmission in the selected speed ratio.

In the operation of our transmission when the vehicle operator desires to depress the pedal remote control, preferably prior to the selection of a new speed ratio, during the first one-third of the maximum movement of the maximum travel of the pedal face 234 the yoke portion 206 moves the abutment member 208 sufficiently away from the cylindrical portion 209 to effect a decrease in the fluid pressure to about one-half of the predetermined maximum fluid pressurethe speed ratio controlling device 32, 33, 34 or 35 providing the prior speed ratio drive in the meantime being operated with less and less pressure in cylinder 202 and consequently with more and more slippage of the drum 31.

Completion of the pedal travel moves the abutment member 208 further and further away from the cylindrical portion 209 to its Fig. 14'condition, and very gradually decreases the fluid pressure to about one-third of the predetermined maximum pressure so that the selected controlling device 32 to 35 is operated by less and less pressure in the cylinder 202 until there is just sufllcient pressure to prevent the drum 31 from slipping undesirably. At the extreme of the pedal movement the link 2I8 closes the switch I82 to move the solenoid armature rearwardly to completely release all the controlling devices 32 to 35.

On the return movement of the pedal face 234,

time the fluid pressure is once more at the predetermined maximum.

As described the increased slippage of the drum 31 is very gradual as the pedal face 234 is depressed. Furthermore, the relationship of the arm support 223 to the link support 228 is such that one-half of the maximum fluid pressure is reduced while the pedal face travels about onethird of its total movement, and that the fluid pressure is further gradually reduced to about one-third of its predetermined maximum as the pedal movement is completed, at which time the switch I82 is closed to give a neutral position for the transmission C. The vehicle operator always efiects a smooth and quiet speed ratio change as he desires, inasmuch as the slippage of the selected controlling device is high until the pedal face 234 is nearly at its Fig. 1 position. The downward or the upward travel of the pedal face 234 can be made in one movement if desired, and the operation of our variable regulating means in response thereto is almost instantaneous.

It is unnecessary for the vehicle driver to completely depress the pedal face while selecting a speed ratio. For example, he may depress the pedal face to a predetermined distance to efiect a predetermined amount of slippage of the selected controlling device-depending on the kind of vehicle performance he desires. On the other hand, he need not move the pedal face at all while selecting a speed ratio, for the fluid clutch B and the speed ratio controlling device will absorb to a great extent any harsh action resulting from such a power shift.

It is not our intention to limit our invention to the degrees of fluid pressure control hereinbefore described, since these are for illustrative purposes only; and other forms of suitable remote controls may be used if desired.

The selector operating mechanism is practically instantaneous in its response to selective adjustment of the lever I53 and the different selections may be made as rapidly as desired. In the general operation of the selector mechanism E for changing the transmissionspeed' ratio, the operator depresses the pedal face 234 if he desires certain speed ratio change characteristics at that instant, andlifts the selector lever I53 from one of the station notches in the switch member I65. Just as soon as the pedal face 234 is completely depressed the switch I82 will be closed to reduce the fluid pressure to practically zero by moving the valve I2I rearwardly which will consequently reduce the fluid pressure in the cylinder 25I. 0n the other hand, if the pedal face is not depressed at all or not sufliciently to close the switch I82, just as soon as the selector lever is moved from one of the notches, the switch I12 associated with such notch will be closed-thereby inducing an electrical circuit through the wire I15 to the solenoid windings I18 for moving the solenoid armature I44 rearwardly. This rearward movement of the solenoid armature will adjust the valve I2I rearwardly to place the fluid pressure chamber I18 of cylinder H2 in communication with the reservoir discharge conduit I 48 whereupon the spring F will move the shaft D rearwardly to release any ofthe controlling devices 32 to 35 which might have been in operation.

During this opening of the chamber '6 to the conduit I48 the fluid pressure in the cylinders 202 and 25I is substantially lowered at which time the cam link 231 may easily be moved vertically because the piston- 241 is not forcing the end portion 248 against the cam link. The selector lever I53 may then be swung to any other station of control and simultaneously the cam link 231 moves vertically to its newly selected position: i. e., for second and third, first and reverse speed ratio the cam surfaces 242, 240 and 243 respectively are adjacent the end portion 248 to control the pressure of the spring 204 against pressure on the shaft D for operating one of the selector controlling devices, or else for effecting the neutral condition of the transmission C.

Q vInstantaneously upon this forward travel of the valve I2I the fluid pressure system is again closed and the stroke of the pistons I88, after the pedal face234 is substantially returned, is increased to effect the fluid pressure determined by the newly selected cam surface 240, 242, or 243 and its effect on the spring 204 through the piston 24! and the bell crank 24I.

The speed ratio change having been made with the selector arm I53, the vehicle operator then returns the pedal face 234-providing he has depressed it-to its normal position which causes the selected speed ratio controlling device during that pedal face movement to smoothly and quietly increase its braking effect on the drum in providing the newly selected speed ratio. If, however, the pedal face had been fully depressed before the speed ratio selection, upon concluding this selection the vehicle driver allows the pedal face to return to its normal position of Fig. 1 to effect the desired speed ratio drive. During this return movement of the pedal face the switch I82 is allowed to open again and return the armature I44 and the valve I2I, and this rearward movement of the valve I2I does not occur even though the selector lever I53 has already been moved into the notch corresponding to the newly selected speed ratio and opened that particular switch to interrupt the electrical circuit through the wire I15 to the solenoid windings I82, inasmuch as an electrical circuit is still provided through the switch I82 to keep the valve I2I in its rearward position.

In operating our transmission the various speed ratio selections may be made quickly and easily, aided by the speed ratio controlling device engagement characteristics effected by depressing the pedal to suit the driver's desire, and each speed ratio controlling device is energized sufliciently to satisfactorily handle the torque transmitted by the engine A through that gear train. This also allows a wider range in designing power transmitting devices inasmuch as each speed ratio may reasonably be out of proportions with the others.

Bearing pressures and possibilities of the failure of parts are decreased by our variable regulating means by reason of the fluid pressure for each speed ratio controlling device being just sufficient to handle the torque transmitted through each particular speed ratio. The moving parts are therefore not subjected to continumace-17o ous excess pressures and the pump H need not maintain the compromise. high fluid pressure necessary without our variable regulating means. A suitable remote control such as the illustrated pedal 2I3 is particularly desirable, among other advantages, in operating our variable regulating means when starting the vehicle motor in cold weather, inasmuch as the speed ratio controlling devices are allowed to slip to suit the driver's convenience as he depresses the pedal preparatory to warming up the engine or to making the speed ratio changes while driving the vehicle. 'Without our arrangement the vehicle would creep by reason of this particular char- "acteristic of the fluid coupling B and the fact that the oil on the speed ratio controlling devices is .cold and tacky, and furthermore the engagement of these controlling devices would be harsh because of the high fluid press re produced by the pump when the engine is i ing fast-all of which tends to effect unevenness of control and stalling of the engine.

Referring to Fig. 18 in which we have illus-v trated a modified embodiment, it will be understood that this modifled arrangement is intended to be substituted for the parts previously described and the entire mechanism and its operation will not again be duplicated. Parts of similar function but different construction have been indicated by primed reference characters.

It will be noted that we have eliminated the pedal control so that our variable regulating means is entirely responsive to the selection of a station with the selector lever I 53. v

The piston 203 is adapted to reciprocate within the cylinder 202 and is urged rearwardly by a heavy spring 204' which surrounds a piston rod I 98' and abuts against the member 205 journalled on the rod I98.

.In the operatioii of this embodiment of our invention the piston 203 moves forwardly in response to the fluid pressure within the cylinder 202 as the fluid is delivered by the pump H through the intermediary of the outlet passage I88 and the conduit 2I0 to the inlet 2 of the accumulator cylinder 202. The cylinder I is continuously exposed to the pressure in the conduit 2I0 and when the cam link 231 is in its illustrated first speed position, the pump continues to increase the pressure to the predetermined amount determined by the rate of the spring 204' bearing against the piston 203. Similarly, if the second and third speed'cam surface 242 or the reverse speed cam surface 243 is adjacent the end'portion 249, the fluid pressure in the system will be increased by the pump H to a predetermined pressure before levelling off the swash plate I90.

In operating the vehicle the driver merely lifts the lever in selecting a different speed ratio which adjusts the valve I2I rearwardly to place the fluid pressure chamber H6 in communication with the reservoir discharge conduit I48 at which time the fluid pressure in the cylinder 25I is reduced to permit the cam link 23'! to be adjusted to its new position 240, 242 or 243 when the selector-lever I53 is swung to its newly selected notch and released therein to cause the valve I2I to move forwardly to operate the transmission in the selected speed ratio. The various speed ratios may be selected easily and quickly, and the pump H furnishes in response to the camlink settings 240, 242 and 243 a predetermined pressure to satisfactorily energize each of the speedratlo controlling devices 32, 33 and 34, and 35 respectively to control the torque transmitted by the engine A through the selected controlling device.

Various modifications and changes will be apparent from the teachings of our invention as set forth in the appended claims, and it is not our intention to limit our invention to the particular details of construction and operation shown and described for'illustrative purposes.

What we claim is:

1. In a motor vehicle transmission having a plurafity of speed ratio controlling devices, pressure fluid operated means including a common operating member for selectively operating said devices, manually operable means for controlling the selective operation of said operating member, means for supplying pressure fluid to said member, and means operable by said manually operable selector means for varying the pressure of the fluid supplied to said member.

2. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means including a common operating member for selectively operatingsaid devices, manually operable means for controlling the selective operation of said operating member, means for supplying presssure fluid to said member, pressure responsive means for controlling the pressure fluid supply to said member, and means operable by said manually operable selector means for causing said pressure responsive member to vary the pressure of the fluid supplied to said member.

3. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means including a common operating member for selectively operating said devices, manually operable means for controlling the selective operation of said operating member, means for supplying pressure fluid to said member, including an element movable by fluid pressure in said supply means for controlling the pressure of the fluid supplied to said member, yielding means opposing fluid presssure movement of said element, and pressure responsive means operable to vary the opposition of said yielding means opposing fluid pressure movesaid element.

4. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means including a common operating member for selectively operating said devices, manually operable meansfor controlling the selective operation of said operating member, means for supplying pressure fluid to said member, including a fluid pressure operated element for controlling the pressure fluid supply to said member, yielding means opposing fluid pressure operation of said element, pressure responsive means for varying the opposition of said yielding means to fluid pressure operation of said element, and means operable by said manually operable selector means for varying the efl'ective "opposition of said pressure responsive means to said yielding means.

5. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means for selectively operating said devices, means for controlling the selective operation of said pressure fluid operated means, means for supplying pressure fluid to said pressure operated means, mechanism responsive to the pressure of fluid delivered by said supply means for controlling the pressure of the fluid delivered by the latter, and means operable by said control means for causing said mechanism means, means for supplying pressure fluid to said to vary the pressure delivered by said supply pressure operated means, mechanism for regulating the pressure of fluid delivered by said supply means, said mechanism including a member responsive to the pressure of fluid delivered by said supply means, means opposing. the action of said pressure responsive member, and means responsive to operation of said selector means for varying the bpposition of the means opposing the action of said pressure responsive member.

17. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means for selectively operating said devices, means for supplying pressure fluid to said pressure operated means, means including an element operable by the pressure of fluid delivered by said supply means for controlling the pressure of the fluid delivered by.

the latter, said control means further includin a second pressure fluid operated element acting in opposition to said first mentioned element, and means for varying the effective Opp ition of said second mentioned pressure responsive element to fluid pressure operation of said first mentioned element.

8. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means for selectively operating said devices, means for controlling the selective operation of said pressure fluid operated means, means for supplying pressure fluid to said pressure operated means, means including an element operable by pressure of fluid delivered by.said supply means for controlling the pressure of the fluid delivered by the latter, said control means further including a second pressure fluid operated element acting in opposition to said first mentioned element, and means operable by said selector means for varying the effective opposition of said second mentioned element to fluid pressure operation of said first mentioned element.

9. In a motor vehicle transmission having a plurality. of speed ratio controlling devices, pressure fluid operated means for selectively operating said devices, means for controlling the selective operation of said pressure fluid operated means, means including a pump for supplying pressure fluid to said pressure operated means, and means operable in response to operation of said control means for varying the operation of said pump.

10.1n a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means for selectively operating said devices, means for controlling the selective operation of said pressure fluid operated means, means including a pump for supplying pressure fluid to said pressure operated means, and means operable in response to operation of said control means for substantially predetermining the maximum fluid displacement of said pump.

, 11. In a motor vehicle transmission having aplurality of speed ratio controlling devices, presmeans, means including a pump for supplying pressure fluid to said pressure operated means,

said pump comprising a plurality of reciprocating pistons delivering fluid under'pressure for operation or said pressure operated means, a wabble plate structure'for controlling the pressure of fluid delivered by said pistons, pressure fluid responsive means for controlling said wabble plate structure, and means responsive to operation of said selector means for varying the control of said wabble plate structure by said pressure responsive means.

12. In a motor vehicle transmission including a plurality of selectively operable fluid pressure operated speed ratio controlling devices constructed and arranged for operation at relatively differing predetermined pressures of fluid, pressure fluid operating means including a common operating member for selectively operating said devices, manually'o'perabie means for controlling the selective operation or said member, means 'ior supplying pressure fluid to said member, and means operable by said selector means in response to the selective operation of one of said devices for causing supply means to deliver a fluid pressure to said. member substantially corresponding to said predetermined operating fluid pressure of the device selected.

13. In a motor vehicle transmission including a plurality of selectively operable fluid pressure operated speed ratio controlling devices con- 'structed and arranged for operation at relatively diflering-predetermined pressures of fluid, pressure fluid operating means including a common operating member for selectively operating said devices, manually operable means for controlling the selective operation of said member, means for supplying pressure fluidto said member, control mechanism for predetermining the fluid pressure delivered to said member, and means operable by said selector means in response to the selective operation of one of said devices for conditioning said control mechanism to cause said supply means to deliver a predetermined fluid pressure to said member substantially corresponding to said predetermined operating fluid pressure of the device selected.

14. In a motor vehicle transmission having a plurality of speed ratio controlling devices, fluid pressure operated means including a common operating member for selectively operating said devices, manually operable means for controlling the selective operation of said operating member, means including a pump for supplying pressure fluid to said member, valve mechanism actuatable in response to operation of said manually operable means for controlling the supply of pressure fluid to said operating member, and means operable by said manually operable means for varying the pressure of fluid delivered bysaid pump.

means for supplying pressure fluid to said member, mechanism operable in response to operation' of said manually operable means for controlling the operation of said member, and means operable by said manually operable means for regulating the pressure 01' fluid delivered by said supply means.

16. In a motor vehicle power transmitting varying to said device, selector lation of said driver manipulated means in opera tively selecting one of said devices for causing said pump to deliver a fluid pressure substantially corresponding to said predetermined operating fluid pressure of the device selected.

- 17. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, means for controlling the selective operation of said devices, a pump for supplying a fluid under operating pressure for operation of said devices,

andmeans operable by said control means for the fluid delivery output of said pump. v 18. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, means for controlling the selective operation of said devices, means for supplying a fluid under operating pressure for operation of said devices, mechanism for varying the pressure of fluid dedeliveredby said supply means.

19. In a motor vehicle power transmitting operable to cause selective operation of said devices, a pump for supplying a fluid under oper-' atmg pressurejo said devices, and means responsive to operation of said vehicle driver operated means to cause selective operation of said devices for varying the fluid delivery output of said p p- 20. In a power transmitting device including a fluid pressure operated drive control device, a pump for supplying a fluid under operating pressure to said device, valve means operable to con trol the communication of fluid from said pump means operable to eifect operation of said valve means, and means responsive to operation of said selector means to effect operation of said valve means for varying the pressure of fluid delivered by said pump.

21. In a power transmitting mechanism including a plurality of drive control devices, a plurality of fluid pressure operated braking devices for respectively operating said speed ratio controlling devices, a pump for supplying a'fluid under operating pressure for operation of said brake devices, means including a manually operable member for selectively controlling operation of said braking devices, and means responsive to operation of said manually operable member for varying the pressure of fluid delivered by said pump.

22. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, means for controlling the selective operation of said devices, a pump for supplying a fluid under operating pressure for operation of said devices, and means operable in response to operation of said control means for varying the operation of said pump.

23. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, means operable to effect selective operation of said devices, a pump for supplying a fluid under operating pressure for operation of said devices, valve means operable in response to operation of said first mentioned means for controlling fluid pressure operation of said devices, and means operable in response to operation of said first mentioned means to effect operation of said valve means to vary the fluid delivery output of said pump.

24. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means including a common operating member for selectively operating said devices, manually operable means for controlling the selective operation of said operating member, means for supplying pressure fluid to said member, and means operable by said member in response to selective operation of the latter by said manually operable means for regulating the pressure of the fluid supply to said member.

25. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means including a common operating member for selectively operating said devices, manually operable means for controlling the selective operation of said operating memr means for supplying pressure fluid to said member, pressure responsive means for controlling the pressure delivery of said supply means, and means operable by said member in response to the selective operation of the latter by said manually operable means for causing the pressure responsive means to vary the pressure of fluid delivery of said supply means.

26. In a motor vehicle transmission having a plurality of speed ratio controlling devices, pressure fluid operated means for selectively operating said devices, means for controlling the selective operation of said pressure fluid operated means, means for supplying pressure fluid to said pressure operated means, and means operable by said pressure fluid operated means in response to selective operation thereof for controlling the pressure of fluid delivered by said supply means.

27. In a power transmitting mechanism including a plurality of selectively operable fluid pressure operated speed ratio controlling devices, means including a common operating member for selectively operating said devices, manually operable means controlling operation of said member, a pump operable to supply fluid under pressure for operation of said devices, and means operable by said member for regulating the operation of said pump.

WILLIAM T. DUNN. TENO IAVELLI.

CERTIFICATE OF CORRECTION Patent No. 2,205,11170. June 2 191p.

WILLIAM T. DUNN, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 11, first column, line 14.0, claim 5, before the word "including" insert -means--; line 11.6, same claim, for "opposing fluid pressure m0ve-" read to fluid pressure movement of--; line 55, claim 14,, before "including" insert -means--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 25th day of February, A. D. 19m.

Henry Van Arsdale,

( Acting Commis sioner of Patents. 

